Electronic products, particularly electronic products capable of outputting sound, are becoming increasingly smaller due to technological advancement, and electronic products are connected to various types of sound outputting devices. Particularly, functions of sound outputting electronic products, such as MP3 players, are being integrated into smartphones as smartphone develop, and as reliability and simplicity of wireless communication have emerged, recent smartphones may be connected to sound outputting devices configured to use various types of wireless communication technologies.
Various types of the audio outputting devices have been proposed to improve sound shielding from external noise. Among them, although kernel-type earphones to be inserted into user's auditory canals are widely used, the kernel-type earphones have an inconvenience in that additional ear tips have to be purchased and used in order to achieve a fitting sensation while wearing because the user's auditory canals are not constant in diameter, and there is a problem in that pain occurs in the ears when the kernel-type earphones are used for a long time.
Recently, headsets configured to cover the whole ear to improve sound shielding have been in the spotlight again due to the application of wireless communication technology such as Bluetooth technology.
Bluetooth signals may be transferred directionlessly and process sound and data simultaneously. In addition, Bluetooth devices have advantages in that a Bluetooth device can have a pairing function to be used with one or multiple devices, and in that signals thereof can be exchanged through a wall without limitation of a signal transmission angle.
In order to use such a Bluetooth device, a circuit part and a power source for driving the Bluetooth chip are needed, and generally, power is supplied by a battery. Here, although a conventional dry cell battery may be used as the battery, a chargeable battery is lately being widely used as the battery to improve user convenience.
Such a battery is generally formed to be embedded in a housing forming a headset. Accordingly, a space for accommodating the battery is needed, and a size of the housing forming the headset becomes large to accommodate a large size battery in order to implement a high capacity battery, and thus, as the capacity of the battery increases, the weight thereof increases, and thus user convenience decreases.
Particularly, in the case of the headset, since, in contrast to a conventional earphone, a large speaker unit is driven, more power consumption is needed. Accordingly, a battery of a limited size installed in the housing has a limitation of having a short usage time.